Pipe A can fill an irrigation water tank in 4 hours, while Pipe B can fill the same tank in 6 hours. How long will both pipes take working together?
Answer and explanation
Correct answer: D. 2 hours 24 minutes
- Step 1: Work rates: Pipe A fills per hour; Pipe B fills per hour. Step 2. Combined rate: per hour. Step 3. Total time: . Answer: 2 hours 24 minutes. Why not the others: Taking the simple average gives 5 hours.
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